Pneumatic tires

ABSTRACT

A pneumatic tire in which the tire is built by arranging a layer of an elastic material, such as rubber, radially outwardly of a reinforcement layer extending from one bead region to the other bead region of the tire and formed of at least one reinforcement member which has its one end located at either one of the bead regions and is wound up helically or circumferentially in a direction at an angle of 0* to 20* with respect to the rotating direction of the tire, whereby the number of the cut ends of said at least one reinforcement member is substantially decreased, the resistance of the tire to centrifugal force is increased over the entire area of the tire, the occurrence of steady wave is prevented and the tire withstands high speed rotation.

[451 Feb. 5, 1974 PNEUMATIC TIRES [75] Inventor:

[73] Assignee: The Yokohama Rubber Company,

Limited, Tokyo, Japan [22] Filed: June 12, 1972 [21] Appl. No.: 261,675

Takashi Kobayashi, Fujisawa, Japan [30] Foreign Application PriorityData June 12, 1971 Japan 46/41409 [52] U.S. Cl. 152/356, 152/362 R [51]Int. Cl. B60c 9/02, 1360C 15/04 [58] Field of Search... 152/352, 354,355, 356, 357, 152/359, 361 R, 362 R 2,945,525 7/1960 Lugli 152/361 R3,607,497 9/1971 Chrobak 1 152/361 R 2,688,983 9/1954 Bowerman 152/356Primary Examiner-Gerald M. Forlenza Assistant Examiner-Robert SaiferAttorney, Agent, or FirmArmstrong & Wegner [57] ABSIRACT A pneumatictire in which the tire is built by arranging a layer of an elasticmaterial, such as rubber, radially outwardly of a reinforcement layerextending from one bead region to the other bead region of the tire andformed of at least one reinforcement member which has its one endlocated at either one of the bead regions and is wound up helically orcircumferentially in a direction at an angle of 0 to 20 with respect tothe rotating direction of the tire, whereby the number of the cut endsof said at least one reinforcement member is substantially decreased,the resistance of the tire to centrifugal force is increased over theentire area of the tire, the occurrence of steady wave is prevented andthe tire withstands high speed rotation.

7 Claims, 15 Drawing Figures PAIENTEUFEB 51914 SHEET 1 BF 4 FIG. I

FIG.2

FIG.3

PATENTED 5W 3.789.899

sum 2 0r 4 PATENTED 5974 3,789,899

SHEET 3 BF 4 PATENTEU 51974 3.789.899

SHEEI b [If 4 PNEUMATIC TIRES BACKGROUND OF THE INVENTION This inventionrelates to pneumatic tires.

As is obvious, the rotating speed of a tire increases with the speed ofthe vehicle on which the tire is mounted and the force of radialexpansion of the tire due to the centrifugal force becomes large inproportion to a square of speed. A tire capable of following the vehiclespeed cannot be produced unless the circumferential rigidity of the tireis increased to the possible extent to raise the lower limit of speed atwhich steady wave occurs and the radius of curvature of the tire in theradial direction is made large to the possible extent.

It is expected that the vehicle speed will exceed 250 km/hour and reachas high as 500 km/hour in the near future. It has been found that, inthis case, the configuration of the tire reaches 0.2-0.4 in terms ofaspect ratio and a reinforcement member required as an internalreinforcement element of the tire is required to increase only thecircumferential rigidity of the tire and the stresses acting in theradial direction of the tire are very small and of the order of 25percent of the stresses which the presently used tires of an aspectratio of about 0.8 are required to withstand, so that a material whichwill bind a rubber compound to some extent will be sufficient for usefor additional reinforcement of the tire in the radial direction.

With the construction of the presently used radial tires, it issubstantially impossible to prevent the occurrence of a steady wave atthe maximum diameter portion of the side wall of the tire where abreaker layer is not present, i.e., the portion immediately below thetire shoulder, at speeds higher than 300 km/hour. Even when the tire isused at speeds below 300 km/hour, the side wall of the tire, except fora very small specific portion, need to be protected by a cord layerarranged in other than the radial direction. Under these circumstances,there is a tendency to change the tire construction from the radialconstruction to a carcass construction wherein cords are arranged incrossing relation, for increasing the speed capability of the tire.

In the speed region exceeding 300 km/hour, the conventional radialconstruction will be hazardous due to a steady wave, unless the internalpressure of the tire is increased to an extremely high level. But theradial construction does not have an element which solves this problemat the side wall of the tire connected to the shoulder, which is theweakest portion of the tire. Thus, another construction is called forwhich will overcome this disadvantage in the radial construction.

Another disadvantage in conventional tires is the danger inherent to atire the separation of the reinforcement layer and the rubber compounddue to a degradation of physical properties of the rubber compound,particularly the rubber compound connected to the reinforcement cordlayer, caused by heat and to a degradation of bonding strength betweenthe reinforcement layer and rubber compound.

Of particular importance is the separation of the reinforcement layerand the rubber compound due to the absence of an adhesive at the cutends of the cords and a rigidity change of the cords at their ends evenunder the speed and load conditions of the presently used vehicles.

SUMMARY OF THE INVENTION The present invention, therefore, contemplatesthe provision of a pneumatic tire which is characterized in that a tirereinforcement layer is arranged only in a direction perpendicular to thedirection of deflection of the tire or only in the circumferentialdirection of the tire so as to substantially decrease the number of thecut ends of the reinforcement materials. The ends of the reinforcementmaterials imbedded in the bead portions where the deformation stressesare relatively small. This minimizes the effect of the stresses, causedby the internal strain of the tire, on the bonding strength between thecords and rubber compound. The tire having such a circumferentiallyarranged reinforcement layer will have a construction in which therolling resistance is smallest and the concentration of stressesresulting from deflection of the tire is minimized, but the springconstant tends to increase.

According to this novel construction the reinforcement layer takescompressive forces in the longitudinal direction of the cordsconstituting the reinforcement layer, only when the tire is driven andbraked. Therefore, it is not essential to arrange twisting cordshelically in the circumferential direction and, in some cases, the tirecan even be built simply by helically or circumferentially winding metalbands or sheets of a laminate consisting ofa synthetic resin film and anelastic rubbery material, which are not highly resistive to compressionfatigue. These helical or circumferential reinforcement bands or sheetsare not necessarily arranged extending from the bead on one side to thebead on the other side ofthe tire, but may be arranged in two layers insuch a manner that the reinforcement bands or sheets of one layerintersect those of the other layer at a small angle. At any rate, thetire of the present invention is characterized in that these cords ofreinforcement members are arranged in or substantially circumferentialdirection of the tire and the ends thereof are mostly embeded in thebead regions or portions of the tire adjacent the bead regions. Namely,the centrifugal force of the tire increases with speed, and willincrease even to a degree sufficient to support the load imposed on thetire. Therefore, the tire of the present invention is capable ofpreventing the occurrence of a steady wave. The internal pressure shouldbe just enough to secure the lateral rigidity of the tire and there isno necessity for increasing the internal pressure to an excessively highlevel. The construction must be such that the load on the tire issupported without causing an excessively large deflection of the tire.

The centrifugal force F imposed on a tire is expressed by the formula,

wherein W the weight of the deflected tire portion by load,

V the vehicle speed,

r= the radius of the tire.

Suppose that the centrifugal force F is equal to the load G imposed onthe tire, under the conditions that G 800 kg, V 250 km/h 69 m/sec and r=0.35 m,

and hence w 0.576 kg.

Namely, the weight imposed on the deflected portion of the tire is 0.576kg. When the ground-contacting angle of the tread surface of the tire,which is actually deflected (the angle defined by two straight linesconnecting the opposite ends of the ground-contacting length of thetread with the center of the axle) is 30 and the weight of the deformedportion, capable of taking the load G, of the tire having a total weightof kg, that is, the weight of the entire circumferential portion of thetire associating with the centrifugal force, is 7 Namely, W of 0.58 kgcan be expected.

The above calculation has the following significance: Namely, if theground-contacting angle of 30 can be maintained during running of thetire along a straight line at a speed of 250 kg/h, as mentioned above,only by the centrifugal force the tire would be able to support thetotal load thereof, during running, even if the internal pressurethereof is 0.

Now, lets consider the case in which a vehicle with the conventionaltires travels at the normal speed. When W is calculated from the formulagiven above under the conditions that the running speed of the tire 125km/hr, the load imposed on one tire 400 kg, the radius of the tire 0.3m, the total weight of the tire 7 kg, the weight of the tire portionradially displaced due to deflection of the tire, which is obtained byintegrating the total weight of the tire, that is, 7 kg over the entirecircumference of the tire 5 kg and the groundcontacting angle 30, thecalculation result shows that, while W required for supporting the load,imposed on one tire by the centrifugal force only is 0.986 kg, W of 0.41kg can only be expected for the tire described above. In other words,under the conditions set forth above, the load which must be supportedby the internal pressure and the rigidity of the tire is However, duringactual running of the tire, the deflection of the tire is variabledepending upon the interrelating bearing force of the centrifugal force,bearing force of the tire internal pressure and bearing force of thetire rigidity. These three component forces undergo the influence oftemperature change at each portion of the tire.

Namely, deflection of the tire during running at a low speed decreaseswith the speed increasing and, when the tire is repeatedly subjected tosuch deflection, the shearing, compressive and tensile stresses andstrains in the interior of the tire change at a cycle proportional tothe speed. The energy loss attributable to such changes results ingeneration of heat which accelerates the fatigue destruction of thetire.

In a bias tire or radial tire in which complicated internal stressesoccur, the weak points of the tire, such as the shoulders and the upperportions of the beads, are subjected to fatigue destruction more quicklyas the speed and hence the deflection of the tire increases, due to theincreases of the internal stresses and strains.

Therefore, in order for the conventional tires to be durable with highspeed running, it becomes necessary to minimize the tire deflection byincreasing the internal pressure and thereby minimizing the changes ofstresses and strains occurring by reason of the construction of thetires. This means that the bearing capacity of the centrifugal force iswastefully decreased and the dynamic spring constant of the tire isundesirably made extremely large.

In the tire according to the present invention, the internal stressesdue to deflection of the tire are very simple and there is no pointwhere the stresses are concentrated, thus it is unnecessary to make thetire s internal pressure particularly high during running at highspeeds. Therefore, the tire of the invention has the advantages that thebearing capacity of the centrifugal force can be effectively utilizedduring the running the of the tire at high speeds and that the dynamicspring constant of the tire can be maintained at an unexpectedly lowlevel during running of the tire at high speeds.

The construction of the tire according to the present invention havingreinforcement materials wound at an angle of 0 20 to the circumferentialdirection of the tire from the tire beads over the side walls, shouldersand crown of the tire, provides no cause of stress-strain concentration.

Further, in the tire of the present invention the expansion of the tireunder the influence of centrifugal force is prevented by thecircumferential reinforcement members as opposed to radial tire the sidewalls of the tires in which expands outwardly under the influence ofcentrifugal force, with the results that the tire deforms into asubstantially square cross section, with strong stress concentrationoccuring at the shoulders and the shoulder surfaces of the tire treadbeing subjected to an abnormally high pressure.

From the foregoing description, the total load G imposed on a tire maybe expressed approximately by the following simple formula: I

G I/g) '(V /r) PA R...

= the load borne by centrifugal force the load borne by the tireinternal pressure the load borne by the tire rigidity wherein I V thevehicle speed,

r the radius of the tire,

P the tire internal pressure,

A the effective pressure receiving area of the tire deflected surface,

R the repulsive force of the tire resulting from the tire rigidity whenthe tire is deflected. The vertical spring constant K of the tire isexpressed by a partial differential value of the load G with respect torising direction of deflection (X) of the tire. Namely,

in comparing the tire of the present invention and the conventionaltires in terms of formula (A), in the former less heat is generated dueto deflection and hence the internal pressure P is lower than in thelatter. Accordingly, in case of the tire of this invention the firstterm is larger and the second term is smaller than in case of theconventional tires. Further, the third term in case of the presentinvention becomes smaller with the temperature, whereas in case of theconventional tires it becomes larger with the speed increasing. Stillfurther, in case of the tire of this invention the load bearing capacitycan be increased by increasing the internal pressure P of the tire. Inthis sense, it may be said that the tire according to this invention isofa construction having excess load bearing capacity.

With regard to formula (B), it is important to make the first term smallfor improving the riding comfort of the passenger during travel of thevehicle at high speeds. Namely, it is essential to reduce the amount ofchange AW with respect to unit deflection Ax. This in turn makes itnecessary to minimize the weight of the portion where the radius ofrotation is large and to minimize the weights of not only the tire treadportion but also the reinforcement layer.

The most effective way of using the reinforcement members with respectto large centrifugal force is to arrange the reinforcement members at anangle close to 0, and this is particularly important where thereinforcement materials used have a large specific gravity. It can besaid that the construction of the tire according to this invention isadequate also from the standpoint of decreasing the spring constantduring running at high speeds.

As described above, the tire of the present invention is characterizedby the high level of steady wave generating speed, generation of a smallamount of heat, excess load bearing capacity, and steady spring constantat high speeds and stable operation at high speeds. These characteristicfeatures of the tire construction according to the invention produce atire which will take the place of the radial tire in the future when thevehicle speed is high.

The object of the present invention is to provide a pneumatic tire inwhich the tire is built by arranging a layer of an elastic material,such as rubber, radially outwardly which respect to a reinforcementlayer extending from the bead region on one side to the bead region onthe other side of the tire and formed of at least one reinforcementmember. At least one reinforcement member has its one end located ateither one of the bead regions and is wound in a direction at an angleof O20 with respect to the direction of rotation of the tire. In thismanner resistance to centrifugal force is increased over the entireregion of the tire and the generation of a steady wave is prevented.

The tire of the construction according to this invention, in practice,can simultaneously have a very excellent cornering characteristic andbecause of the strong tension acts on the reinforcement members,constituting the circumferentially arranged reinforcement layer, of thetire when the tire is subjected to lateral deformation, since thelateral deformation occurs only in a direction to stretch each portionof the tire in the circumferential direction.

The only problem in this tire is that substantially no reinforcementmembers act to reinforce the tire against the forces created by theinternal pressure to the tire, which act tangentially of the tire crosssection expanding the tire in the widthwise direction. When the tire isused for the purposes for which a high internal pressure of the tire isrequired, e.g. for trucks, it becomes necessary to provide auxiliaryreinforcement means such, a combination of an elastic material and acellulosereinforced compound in which the cellulose fibers are mainlyoriented in a radial direction of the tire. The above-mentioned problemmay be solved to some extent by providing a cord layer extending fromthe left side bead to the right side bead of the tire and another cordlayer superimposed on said first cord layer and extending from the rightside bead to the left side bead of the tire, with the constituent cordsof said respective cord layers crossing each other at a small angle, orby providing such cord layers in more than two layers in the mannerdescribed. In this specification the term cellulose-reinforced compoundmeans a compound into which a plurality of cellulose fibers areincorporated in spaced relation with each other.

By arranging the reinforcement layers in a multiplicity of layers,without using any special metallic bead construction, beads can beformed with the same material as the reinforcement material for thecarcass and crown in the same step. This is advantageous in that, in theproduction of the tire of this invention, the carcass and breaker of thetire can be formed by an automatic tape winding method and the tapewinding method can also be employed for the formation of the tread ofthe tire. Thus, all of the tire-building materials can be supplied inthe form ofa tape and the tire can be built with only the a tape-windingoperation. This enables complete automatization of the tire buildingsystem or semiautomatization of the same in which one worker attends toa plurality of tire building sets. The shape of a tire can be changed bysimply changing the shape of a tire building drum drastically from thatof the conventional one, when manual labor has to be limited to aminimum due to shortage of the working population. Such advantage of thepresent invention is quite important in the light of the fact that,under the present circumstances, the radial tires presently used can beproduced by apparatus which is most difficult to automate and bias tirescan be produced by apparatus, the complete automation of which is alsovery difficult. In the automatic production of the tire of thisinvention, the tire building drum used will be of the shape of the tirein which the portions corresponding to the beads are expanded in thewidthwise direction of the tire, and the outer diameter of the tireafter building will be very close to the outer diameter of the tireafter vulcanization.

For vulcanization of the tire, a sectional must be used so that the tiremay be clamped between the mold parts which are moved toward the tireexternally, this is necessary because the outer diameter of theunvulcanized tire is so close to the outer diameter of the tire aftervulcanization and otherwise the expansion of the outer diameter of thetire would be extremely interfered by the reinforcement layer. Thenumber of the parts of this sectional need to be as large as possible.

BRIEF DESCRIPTION OF THE DRAWING Other objects, features and advantagesof the present invention will become apparent from the followingdetailed description when taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a sectional view of an embodiment of the tire according to thepresent invention comprising the reinforcement member shown in FIG. 5,in the stage after making but before vulcanization;

FIG. 2 is a diagrammatical view illustrating the manner of winding thereinforcement member, shown in FIG. 1, in the circumferential directionof the tire from the bead region on one side toward the bead region onthe other side ofthe tire; I

FIG. 3 is a sectional view of another embodiment of the tire of thisinvention comprising the reinforcement member, shown in FIG. 7 or 8 andhaving a substantial width, in the stage after making but beforevulcanization;

FIG. 4 is a diagrammatical view illustrating the manner of winding thereinforcement member shown in FIG. 3;

FIGS. -8 are sectional views of different reinforcement members used inthe tire of this invention, respectively;

FIGS. 9 and 10 exemplify the building drum used in the making of thetire of this invention, of which FIG. 9 is a perspective view showingthe outline of the building drum and FIG. 10 is a vertical sectionalview thereof;

FIG. 11 is a diagrammatical view illustrating the manner of winding thereinforcement member to form a breaker layer and a carcass layerseparately in another embodiment of the invention;

FIGS. 12-15 show different modes of winding of the reinforcement memberaccording to the invention, of which FIG. 12 is a perspective viewshowing the basic mode of winding; FIG. 13 is a perspective view showingthe reinforcement member being wound helically to form a carcass layerand being wound zigzag to form a breaker layer; FIG. 14 is a model viewshowing the reinforcement member being wound in such a manner that theindividual lengths of the reinforcement member intersect at an angle of2a; and FIG. 15 is a perspective view showing a plurality of thereinforcement members concurrently being wound from the bead of thetire.

DESCRIPTION OF THE PREFERRED EMBODIMENT Describing the present inventionin detail with reference to the drawings, the cordor tape-likereinforcement members I, 1', l" and 1" used in the present invention arecomposed of a core 1A or 1B of a material having a low elongation, suchas steel, textile or light alloy, and a sheath 2 of an elastic material,such as rubber, enclosing said core, as shown in FIGS. 5 to 8. At leastone of these reinforcement members is helically or circumferentiallywound on an elastic inner liner 3 such as of rubber (FIG. I) by suitableguide means in such a manner as shown in FIG. 2, namely in a manner toextend from the bead region on one side to the bead region on the otherside of the tire, at an angle of 0-20 to the rotating direction of thetire, thereby to form a reinforcement layer. Further an elastic band 4(FIG. 1) such as a rubber band is wound up on top of said reinforcementlayer to constitute the tread of the tire, wherebyan unvulcanized tireis completed.

FIG. 1 shows in cross section an unvulcanized tire which was made using,for example, the reinforcement member shown in FIG. 5. The side wallportions of the tire are bent as indicated by the phantom line when thetire is vulcanized in a sectional mold, whereby a complete tire isbuilt.

FIG. 4 shows the other procedure of applying the reinforcement member,and FIG. 3 shows an unvulcanized tire made using, for example, thereinforcement member shown in FIG. 7 which is applied according to theprocedure shown in FIG. 4. In the embodiment shown in FIG. 3, the sidewalls of the tire are each provided therein with one reinforcement layerand the crown region thereof with two reinforcement layers, each ofwhich reinforcement layers is formed by the reinforcement member 1"helically wound to extend from the bead region on one side to theshoulder region on the other side of the tire.

FIG. 2 shows an example of the reinforcement member winding method toform the reinforcement layers which constitute a part of the crosssection of the tire shown in FIG. 1. In order to make such arrangementof reinforcement member possible, a building drum is re quired whichmakes the tire in such a shape that the tire has conical side wallshaving a mild angle of inclination 6 (FIG. 2) and a cylindrical crown.For ease in building the tire, the angle 0 preferably does not exceed 50at largest. This drum is composed, for example, of two substantiallyconical, auto-collapsible sectional movable parts 10 which can be openedinto the shape of an umbrella and adapted to be combined together.Projections formed at one end of one of them are received incorresponding notches formed in the facing end of the other one, asshown in FIGS. 9 and 10. A rubber bladder 11 is superimposed on theouter surface of the sectional movable parts as shown in FIG. 10, so asto facilitate the winding of the reinforcement material and removal ofthe shaped tire, e.g. the unvulcanized tire of the type shown in FIG. 1,from the mold.

The use of a cellulose-reinforced compound elastic reinforcementmaterial for the liner 3 shown in FIGS. 1 and 3, the use ofacellulose-reinforced rubber material for the elastic rubber material 2shown in FIGS. 5, 6, 7 and 8, and the use of a cellulose-reinforcedrubber material for the tread-forming elastic material 4 shown in FIGS.1 and 3, to further reinforce the tire in the ra dial direction, are ofcourse included within the scope of this invention as modificationsthereof. A construction gf the tire in which the carcass and breaker areconstituted by a separate cordor tape-like reinforcement member is alsoincluded within the scope of this invention, and an example of suchconstruction is shown in FIG. 11.

Although various combinations of directions in which the reinforcementmembers are arranged are considered, it is practical according to theinvention to arrange the carcass layer-forming reinforcement member atan angle of 02() and the breaker layer-forming reinforcement member atan angle of 020 with respect to the circumferential direction of thetire.

Namely, FIG. l2 shows the case wherein the carcass and breaker layersare at an angle of or close to 0 and FIG. 13 shows the case wherein thecarcass layer is at an angle of or close to 0 and the breakerlayer-forming reinforcement member is at an angle of 0' (about 15) tothe mid-circumferential plane and further the carcass and breaker layersare integrally connected with each other.

It is very important to arrange the reinforcement member of the carcassand breaker layers at an angle not greater than 20 to thecircumferential direction of the tire. This is because of the followingreason: Namely, when the Youngs modulus of a laminate consisting of thereinforcement layers formed by intersecting reinforcement cords isconsidered with reference to a model shown in FIG. 14 and with 2arepresenting the angle of intersection of the cords 0,, representing thestresses of the cords, e representing the strain of the model, Erepresenting the equivalent Youngs modulus What is claimed is:

1. A pneumatic tire in which the tire is built by arranging a layer ofan elastic material, such as rubber, radially outwardly of areinforcement layer extending of the elastic material and the thicknessof the cords 5 f m the bead region on one side to the bead region onbeing ignored,

1 Re (1/2) e.) (a, 0 mm E (1/2) e.) (a, 0 5111 7111 1 aflsinarcosa ahdwhen the infinitesimals of higher order are ignored, considering thecords as being inextensible,

e cos a e sin a 0.

Therefore,

v 6J6, cot a 11,, tan a Further, considering that the tension in thedirection of 20 X axis is uniform, and that 0,, 1-, 0,

a, F6 4 1 cot a cotot) Also, from the Hooks law,

2, l/E (r, r /E 0' 6,, u TI/EJ Therefore,

E, o' /e EH cot a cot a) Similarly, E, EH tan a tana) When the values ofa, E, l E and E are calculated from the foregoing equation,

a E, [5,, 1x1.05(1 0.933 17 104.750 0.915 20 50.435 0.885 17.551 0.68l(1.999 0.778

However, the experiment revealed that the binding force against theincreasing centrifugal force is insufficient when the value of E, l?issmaller than 50 and the value of E, E is preferably more than 100. Inthis sense, it is preferable that the angle of the reinforcement memberto the circumferential direction of the tire is preferably 17 orsmaller.

Although in the embodiments shown, only one cord or reinforcement bandis wound up, it should be understood that a plurality of thereinforcement bands may be concurrently wound helically with their endslocated at the bead region of the tire, as shown in FIG. 15 in which thereinforcement bands are concurrently wound up from three points a, b, c.In this case, three reinforcement layers are formed at the crown and onereinforcement layer at each side wall of the tire in one step of windingthe reinforcement band from the bead on the right side to the bead onthe left side of the tire.

the other side of the tire and formed of at least one reinforcementmember, said at least one reinforcement member having at least one endthereof forming a bead member and being wound up in a direction at anangle of 020 to the rotating direction of the tire wherein said headmember and reinforcement member are continuous whereby the resistance ofthe tire against centrifugal force is increased over the entire regionof the tire and the occurrence of a steady wave is prevented.

2. A pneumatic tire as defined in claim 1, wherein each of said at leastone reinforcement member is composed of a core of a material having lowelongation and a sheath of an elastic material enclosing said core, andis in the shape of a cord or tape.

3. A pneumatic tire as defined in claim 1, wherein said at least onereinforcement member is wound in a multiplicity of layers at the beadregions of the tire to form said bead members.

4. A pneumatic tire as defined in claim 1, wherein there is provided aninner liner located radially inwardly of and extending along saidreinforcement layer and serving as guide means in the winding operationof said reinforcement member, said inner liner consisting of an elasticmaterial into which a plurality of cellulose fibers are incorporated inspaced relation with each other.

5. A pneumatic tire as defined in claim 1, wherein at least one of saidreinforcement members is wound up at the crown region of the tirelocated radially outwardly of said reinforcement layer, to form anadditional reinforcement layer.

6. A pneumatic tire as defined in claim 1, wherein the aspect ratio ofthe tire lies within the range of 0.2-0.4.

7. A pneumatic tire in which at least one reinforcement member extendingfrom the bead region on one side to the shoulder region on the otherside of the tire and at least one reinforcement member extending fromthe bead region on said other side to the shoulder region on said oneside of the tire are respectively wound up at an angle of 0 20 to therotating direction of the tire to form a reinforcement layer, and atleast one bead member wherein the bead member and reinforcement memberare continuous, said second-mentioned at least one reinforcement memberbeing superimposed on said first-mentioned at least one reinforcedmember at the crown region of the tire, and a layer of an elasticmaterial, such as rubber, is arranged radially outwardly of saidreinforcement layer, whereby the resistance of the tire to centrifugalforce is increased over the entire region of the tire and the occurrenceof steady wave is prevented.

1. A pneumatic tire in which the tire is built by arranging a layer ofan elastic material, such as rubber, radially outwardly of areinforcement layer extending from the bead region on one side to thebead region on the other side of the tire and formed of at least onereinforcement member, said at least one reinforcement member having atleast one end thereof forming a bead member and being wound up in adirection at an angle of 0*20* to the rotating direction of the tirewherein said bead member and reinforcement member are continuous wherebythe resistance of the tire against centrifugal force is increased overthe entire region of the tire and the occurrence of a steady wave isprevented.
 2. A pneumatic tire as defined in claim 1, wherein each ofsaid at least one reinforcement member is composed of a core of amaterial having low elongation and a sheath of an elastic materialenclosing said core, and is in the shape of a cord or tape.
 3. Apneumatic tire as defined in claim 1, wherein said at least onereinforcement member is wound in a multiplicity of layers at the beadregions of the tire to form said bead members.
 4. A pneumatic tire asdefined in claim 1, wherein there is provided an inner liner locatedradially inwardly of and extending along said reinforcement layer andserving as guide means in the winding operation of said reinforcementmember, said inner liner consisting of an elastic material into which aplurality of cellulose fibers are incorporated in spaced relation witheach other.
 5. A pneumatic tire as defined in claim 1, wherein at leastone of said reinforcement members is wound up at the crown region of thetire located radially outwardly of said reinforcement layer, to form anadditional reinforcement layer.
 6. A pneumatic tire as defined in claim1, wherein the aspect ratio of the tire lies within the range of0.2-0.4.
 7. A pneumatic tire in which at least one reinforcement memberextending from the bead region on one side to the shoulder region on theother side of the tire and at least one reinforcement member extendingfrom the bead region on said other side to the shoulder region on saidone side of the tire are respectively wound up at an angle of 0* - 20*to the rotating direction of the tire to form a reinforcement layer, andat least one bead member wherein the bead member and reinforcementmember are continuous, said second-mentioned at least one reinforcementmember being superimposed on said first-mentioned at least onereinforced member at the crown region of the tire, and a layer of anelastic material, such as rubber, is arranged radially outwardly of saidreinforcement layer, whereby the resistance of the tire to centrifugalforce is increased over the entire region of the tire and the occurrenceof steady wave is prevented.